L-arginine, a semi-essential amino acid that is naturally produced in the body, has been widely used in medicaments, food, animal feedstuffs, and other products. L-arginine is useful as a drug for improving the hepatic function and brain function and treating male sterility, and as an ingredient of multiple amino acid supplements. Also, L-arginine has been used as a food additive in fish cakes and health beverages, and has recently gained interest as a salt substitute for hypertension patients.
Conventional methods for L-arginine production by biological fermentation are based on the production of L-arginine directly from carbon and nitrogen sources. For example, L-arginine can be produced using a mutant strain derived from a glutamic acid-producing microorganism belonging to the genus Brevibacterium or Corynebacterium (Japanese Pat. Laid-Open Publication Nos. Sho57-163487, Sho60-83593 and Sho62-265988), or using an amino acid-producing microorganism the growth properties of which are improved through cell fusion (Japanese Pat. Laid-Open Publication No. Sho59-158185). Also, L-arginine can be produced using a strain transformed with a recombinant gene (Japanese Pat. Laid-Open Publication No. Sho63-79597 and U.S. Pat. No. 4,775,623).